It is becoming an increasingly widespread practice to perforate the wrappings of cigarettes so as to provide or allow for intake to the cigarette of a dilution air stream during the smoking of the cigarettes. The perforated openings can be formed in various manners and in the cigarette be located either in the tobacco rod or, as is more generally done, perforations can be provided in a cigarette mouthpiece component or in the filter tip of a filtered type cigarette.
U.S. Pat. Nos. 3,701,353 and 4,140,137 each describe apparatus for perforating filter type cigarettes to provide same with dilution apertures in the filter components thereof. Such apparatus is quite satisfactory for the intended purposes inasmuch as it is employed for perforating a single circular row of perforations around a cigarette filter element. Accordingly, only a single perforating means need be employed at one side of a rolling course through which the cigarettes are moved to effect perforation, the perforating means, in the form of needles, being carried in the rolling shoe. On the other hand and where it is desired to perforate a cigarette mouthpiece component which is provided in the form of a hollow relatively rigidized paper cylinder with a plurality of rows of such perforations extending axially spaced along the paper mouthpiece, the apparatus disclosed in the cited patents would not be satisfactory if it were sought to perforate the plural rows by merely providing corresponding plural lines of needles in the rolling shoe member. This is so because the close spacing of the rows if all effected from one side of the cylinder would result in crushing or undersirable shape distortion of the cylinder by the perforating force applied thereto.